Foot-and-mouth disease virus (FMDV), the etiological agent of foot-and-mouth disease (FMD), is a constant threat to domestic livestock throughout the world. FMDV belongs to the aphthovirus genus of the family Picornaviridae. Its viral particle contains a single-stranded RNA genome within an icosahedral capsid consisting of 60 copies of each of four proteins, VP1, VP2, VP3 and VP4. The particle shell is made of the three larger structural proteins, VP1 to VP3, while the smaller VP4 is located internally (Acharya et al. (1989) Nature 337(6209): 709–716).